A polymorphic storage method, polymorphic memory and storage medium

Abstract

The present application discloses a method for multi-state storage, a multi-state memory, and a storage medium. The method includes: changing a current flowing into a heavy metal layer from a first current to a second current, causing the heavy metal layer to generate a target spin current, and generating a first spin-orbit torque in the magnetic field of the free layer in response to the target spin current. Under the action of the first spin-orbit torque, the antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment, and switches the first free layer magnetic moment of the free layer to the second free layer magnetic moment, so that the resistance state of the multi-state memory switches from the first resistance state to the second resistance state. This achieves multi-resistance state storage by controlling the magnitude of the current. Furthermore, since the magnitude of the current is easier to control, this control method makes it easier to obtain more stable multiple resistance states, reducing the difficulty of implementing multi-state storage.

Description

Technical Field

[0001] The present application relates to the field of storage technology, and in particular to a polymorphic storage method, a polymorphic memory, and a storage medium. Background Art

[0002] With the ever-increasing demand for data storage, the need for multi-state non-volatile memory devices has become even more pressing. In multi-state memory devices, a single memory cell can record multiple values, not just "0" and "1." This storage method can significantly increase data density and is also of great benefit to emerging industries such as artificial intelligence and neural networks.

[0003] Currently, multi-state memory devices utilize a spin-orbit torque (SOT) structure. The SOT structure's storage principle utilizes a fixed free layer and a pinned layer arranged in parallel or antiparallel, enabling the multi-state memory device to achieve two resistance states, "0" and "1." Other resistance states require controlling the magnitude of the write magnetic field. Because the write magnetic field is controlled with a precision of 0.1 Oe (Oe stands for Oersted, representing both magnetic field strength and magnetization), the control difficulty is significant. Consequently, the memory device can only achieve two stable resistance states, high and low. Resistance states beyond these two states are difficult to achieve stably, making stable multi-state storage challenging. Summary of the Invention

[0004] In response to the above-mentioned technical problems, the embodiments of the present application propose a polymorphic storage method, a polymorphic memory, and a storage medium to solve the problem that configurations other than the high-resistance state and the low-resistance state are difficult to stably achieve, making it difficult to implement stable polymorphic storage.

[0005] A first aspect of an embodiment of the present application provides a polymorphic storage method, including:

[0006] The method is applied to a multi-state memory, the multi-state memory including a substrate and a magnetic tunnel junction covering the substrate, wherein the upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer and a free layer from bottom to top. The method includes:

[0007] When the current flowing into the heavy metal layer changes from the first current to the second current, the heavy metal layer generates a target spin current, the target spin current flows into the free layer via the antiferromagnetic layer, and the current value of the second current is less than or equal to a first preset value, which is any value in a first preset range;

[0008] The magnetic field of the free layer generates a first spin-orbit torque in response to the target spin current;

[0009] The antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque;

[0010] Under the action of the magnetic moment of the second antiferromagnetic layer, the free layer switches from the first free layer magnetic moment to the second free layer magnetic moment, so that the resistance state of the multi-state memory switches from the first resistance state to the second resistance state, the first resistance state is the resistance state corresponding to the first free layer magnetic moment, and the second resistance state is the resistance state corresponding to the second free layer magnetic moment.

[0011] Preferably, the current flowing into the heavy metal layer is changed from the first current to the second current, comprising:

[0012] When the first current is a current in a first direction, the first current value is the first preset value, the second current is in a direction opposite to the first current, and the current value of the second current is less than the first preset value; or,

[0013] When the first current and the second current have the same direction, the difference between the second current and the first current is N times a second preset value, where N is an integer greater than or equal to 1, and the second preset value is a value within a second preset range that is smaller than the first preset value.

[0014] Preferably, the direction of the magnetic moment of the second antiferromagnetic layer is the same as the direction of the magnetic moment of the second free layer.

[0015] Preferably, the antiferromagnetic layer switches from a first antiferromagnetic layer magnetic moment to a second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from a first free layer magnetic moment to a second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, including:

[0016] One or more first antiferromagnetic layer magnetic sequences of the antiferromagnetic layer are converted into second antiferromagnetic layer magnetic sequences under the action of the first spin-orbit torque, and any one or more second antiferromagnetic layer magnetic sequences of the antiferromagnetic layer serve as the second antiferromagnetic layer magnetic moment;

[0017] One or more first free layer magnetic domains of the free layer are converted into second free layer magnetic domains under the action of the second antiferromagnetic layer magnetic order, and any one or more second free layer magnetic domains of the free layer serve as the second free layer magnetic moment.

[0018] Preferably, the magnetic tunnel junction further includes a fixed layer above the free layer, and the method further includes:

[0019] determining a magnetic moment deflection between a magnetic moment of the second free layer and a magnetic moment of the pinned layer;

[0020] The resistance state corresponding to the magnetic moment deflection is calculated according to the magnetoresistance effect as the second resistance state.

[0021] Preferably, the first preset range is 10 microamperes μA to 10 milliamperes mA.

[0022] Preferably, the second preset range includes the following second preset values: 1 μA, 2.5 μA, 1 mA and 2.5 mA.

[0023] A second aspect of an embodiment of the present application provides a multi-state memory, the multi-state memory comprising:

[0024] a substrate and a magnetic tunnel junction covering the substrate,

[0025] The upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer and a free layer from bottom to top;

[0026] The heavy metal layer is configured to generate a target spin current when the current flowing therein changes from a first current to a second current;

[0027] The antiferromagnetic layer is used to flow the target spin current into the free layer via the antiferromagnetic layer, wherein a current value of the second current is less than or equal to a first preset value, and the first preset value is any value in a first preset range;

[0028] The free layer, the magnetic field used for the free layer generates a first spin-orbit torque in response to the target spin current, the antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from the first free layer magnetic moment to the second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, the first resistance state is the resistance state corresponding to the first free layer magnetic moment, and the second resistance state is the resistance state corresponding to the second free layer magnetic moment.

[0029] Preferably, the magnetic tunnel junction further comprises a fixed layer above the free layer, and the fixed layer is used to determine the magnetic moment deflection between the magnetic moment of the second free layer and the magnetic moment of the fixed layer;

[0030] The resistance state corresponding to the magnetic moment deflection is calculated according to the magnetoresistance effect as the second resistance state.

[0031] A third aspect of the embodiments of the present application provides a storage medium on which computer-executable instructions are stored. When the computer-executable instructions are executed by a computing device, they can be used to implement the methods described in the aforementioned embodiments.

[0032] In an embodiment of the present application, the current flowing through the heavy metal layer is changed from a first current to a second current, the heavy metal layer generates a target spin current, and the magnetic field of the free layer generates a first spin-orbit torque in response to the target spin current, so that the antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and then the first free layer magnetic moment of the free layer is switched to the second free layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, thereby realizing the control of the current size to realize multi-resistance state storage, and the current size is easier to control. This control method is easier to obtain more stable multi-resistance states, reducing the difficulty of realizing multi-state storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The features and advantages of the present application will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present application in any way. In the accompanying drawings:

[0034] Figure 1 This is a flow chart of a polymorphic storage method provided by this application;

[0035] Figure 2 This is a schematic diagram of the structure of a polymorphic memory provided by this application;

[0036] Figure 3 This is another structural diagram of a polymorphic memory provided by this application. DETAILED DESCRIPTION

[0037] In the detailed description below, many specific details of the present application are set forth by example, so that a thorough understanding of the relevant disclosure is provided. However, for those of ordinary skill in the art, it is obvious that the present application can be implemented without these details. It should be understood that the use of "system", "device", "unit" and / or "module" terms in the present application is a method for distinguishing different parts, elements, parts or assemblies at different levels in a sequential arrangement. However, if other expressions can achieve the same purpose, these terms can be replaced by other expressions.

[0038] It should be understood that when a device, unit, or module is referred to as being "on," "connected to," or "coupled to" another device, unit, or module, it may be directly on, connected to, coupled to, or communicating with the other device, unit, or module, or there may be intervening devices, units, or modules, unless the context clearly indicates an exception. For example, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] The terms used in this application are only for describing specific embodiments and are not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified features, wholes, steps, operations, elements and / or components, and such expressions do not constitute an exclusive list, and other features, wholes, steps, operations, elements and / or components may also be included.

[0040] like Figure 1 As shown, this application provides a polymorphic storage method. Figure 1 The illustrated method can be applied to Figure 2 Schematic diagram of polymorphic memory.

[0041] See also Figure 2 An exemplary multistate memory includes a substrate and a magnetic tunnel junction overlying the substrate. The upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer and a free layer from bottom to top. The heavy metal layer is composed of at least one of Ta (tantalum), W (tungsten), WO (tungsten oxide, obtained by oxidation), WN (tungsten nitride, obtained by nitridation), Pt (platinum), Pd (palladium), Hf (hafnium), Au (gold), Hf (hafnium), and Mo (molybdenum). The thickness of the heavy metal layer ranges from 1 nm (nanometer) to 10 nm. Exemplarily, the heavy metal layer can be an alloy of different atomic ratios of the above metal materials, such as Au0.93W0.07, Au0.9Ta0.1, AuxPt100-x, etc.; the heavy metal layer can also be Bi2Se3, Bi2Te3, Sb2Te3 or (BixSb1-x)2Te3 crystal film, etc.; the heavy metal layer can also be BixSe1-x polycrystalline or amorphous film; or WTe2, MoTe2 or MoxW1-xTe2 single crystal, polycrystalline or amorphous outer ear semimetal, etc.; the heavy metal layer can also be any structure that can generate spin current, such as two-dimensional electron gas, etc. The magnetic materials that make up the antiferromagnetic layer include: IrMn (iridium manganese alloy), FeMn (iron manganese), PtMn (platinum manganese alloy), CoTb (cobalt terbium alloy), GdFeCo (gadolinium iron cobalt alloy), etc. The material of the antiferromagnetic layer is not limited to the listed element ratios. For example, the antiferromagnetic layer IrMn can be Ir2Mn or IrMn3.

[0042] See also Figure 1 , the method comprising:

[0043] In step S10 , when the current flowing into the heavy metal layer is changed from the first current to the second current, the heavy metal layer generates a target spin current.

[0044] In step S20 , the target spin current flows into the free layer via the antiferromagnetic layer, and a current value of the second current is less than or equal to a first preset value, where the first preset value is any value within a first preset range.

[0045] In step S30, the magnetic field of the free layer generates a first spin-orbit torque in response to the target spin current, and the antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque. The free layer switches from the first free layer magnetic moment to the second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, wherein the first resistance state is the resistance state corresponding to the first free layer magnetic moment, and the second resistance state is the resistance state corresponding to the second free layer magnetic moment.

[0046] Through the above steps, the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, thereby achieving multi-resistance state storage by controlling the magnitude of the current, and the magnitude of the current is easier to control. This control method is easier to obtain more stable multi-resistance states, reducing the difficulty of implementing polystate storage.

[0047] In one embodiment, the current flowing into the heavy metal layer is changed from a first current to a second current, comprising:

[0048] When the first current is a current in a first direction, the first current value is the first preset value, the second current is in the opposite direction to the first current, and the current value of the second current is less than the first preset value. When the first current and the second current are in the same direction, the difference between the second current and the first current is N times a second preset value, where N is an integer greater than or equal to 1, and the second preset value is a value within a second preset range that is less than the first preset value.

[0049] It should be noted that the first current and the second current can be pulse currents, and the first resistance state formed by the first current control can be the initial state, that is, it indicates that the storage state is "0". In fact, at this time, the storage state of the second resistance state formed by the second current control is "1". If a third resistance state is required, it is necessary to continue to take a new second current with the same direction as the second current, that is, the second current size can be changed. For the convenience of understanding, the new second current is recorded as the third current. The third current value is greater than the second current value, and the third current value is less than the first current value, and so on, until the last current is equal to the first current value, and the corresponding resistance state is obtained in sequence as the third resistance state. Resistance state, fourth resistance state...tenth resistance state, the intermediate process is not repeated here, the third current value is increased compared to the second current value, the magnitude of the increased current is a fixed increase or a regular increase, similarly, the subsequent current value must be greater than the previous current value each time until it equals the first current value and stops, therefore, each corresponding current value increase is a fixed increase or a regular increase, that is, the difference between the second current and the third current is N times the second preset value, N is an integer greater than or equal to 1, and the difference between the second current and the third current is N times the second preset value, is the maximum or less than the maximum value and / or minimum value of the first preset value range. Therefore, by controlling the change between the currents, controlling the change between the first current and the second current, the first free layer magnetic moment can be controlled to switch to the second free layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state. Of course, the first resistance state formed by the first current control can also be an intermediate resistance state, that is, it indicates that the storage state is any one of "1" to "10". At this time, the direction of the second current is required to be the same as the direction of the first current, the magnitude of the second current is greater than the magnitude of the first current, and the magnitude of the second current is gradually increased. The difference between the second current and the first current is N times the second preset value, and it is gradually increased by N times to obtain the corresponding resistance state as the current resistance state, that is, the current resistance state is the second resistance state.

[0050] In another embodiment, the storage state of the present application can also be from "10" to "0". When the direction of the second current is opposite to the direction of the first current, the magnitude of the second current is smaller than the magnitude of the first current. At this time, the storage state of the second resistance state formed by the second current control is "10". If a third resistance state is required, continue to reduce the magnitude of the second current. The magnitude of the current reduced each time forms a corresponding resistance state, and the magnitude of the current reduced each time is a fixed reduction. The difference between the second current and the first current is N times the second preset value, and N is an integer greater than or equal to 1, that is, each time it is reduced to N times the previous value. Of course, the minimum value of the second current does not exceed the minimum value of the second preset range. When the second current is reduced to the minimum preset value, it indicates that the storage state is "0" at this time.

[0051] Preferably, by setting the first current size to any value within the first preset range, that is, by adjusting the first current size, multi-resistance state storage can be achieved, and different first current sizes will affect the value of the second current size. At this time, if different resistance states are to be obtained, it is necessary to gradually increase or decrease the current size on the basis of the second current size, that is, the difference between the second current and the first current satisfies N times the range, and corresponding different resistance states will be obtained.

[0052] In one embodiment, the direction of the magnetic moment of the second antiferromagnetic layer is the same as the direction of the magnetic moment of the second free layer. By changing the direction of the magnetic moment of the second antiferromagnetic layer, the direction of the magnetic moment of the second free layer is changed. Moreover, once the direction of the magnetic moment of the second antiferromagnetic layer is determined, the direction of the current can be determined, and the initial resistance state value can also be confirmed, thereby improving storage stability.

[0053] In one embodiment, the antiferromagnetic layer switches from a first antiferromagnetic layer magnetic moment to a second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from a first free layer magnetic moment to a second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, including:

[0054] Under the action of the first spin-orbit torque, one or more first antiferromagnetic layer magnetic sequences of the antiferromagnetic layer are converted into second antiferromagnetic layer magnetic sequences, and any one or more second antiferromagnetic layer magnetic sequences of the antiferromagnetic layer serve as the second antiferromagnetic layer magnetic moment. Under the action of the second antiferromagnetic layer magnetic sequence, one or more first free layer magnetic domains of the free layer are converted into second free layer magnetic domains, and any one or more second free layer magnetic domains of the free layer serve as the second free layer magnetic moment. By regulating the change in the magnitude and direction of the current, the magnitude of the target spin current is changed, thereby changing at least one of the number, magnitude, and direction of the first antiferromagnetic layer magnetic sequences, and further changing at least one of the number, magnitude, and direction of the first free layer magnetic domains, thereby obtaining the second free layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, and the corresponding resistance state is obtained by calculating the magnetic moment deflection through the magnetoresistance effect.

[0055] In one embodiment, if Figure 2 As shown, the magnetic tunnel junction further includes a pinned layer above the free layer. The magnetic moment deflection between the magnetic moment of the second free layer and the magnetic moment of the pinned layer is determined, and the resistance state corresponding to the magnetic moment deflection is calculated based on the magnetoresistance effect as the second resistance state. Calculating the resistance state requires first determining whether the magnetic moment of the second free layer and the magnetic moment of the pinned layer are parallel or antiparallel. If they are antiparallel, the magnetoresistance is then determined, and the corresponding resistance state is calculated based on the magnetoresistance.

[0056] In another embodiment, the magnetic tunnel junction further includes a non-magnetic barrier layer and a capping layer stacked sequentially, the non-magnetic barrier layer being disposed on the free layer, the fixed layer being disposed on the non-magnetic barrier layer, and the capping layer being disposed on the fixed layer. The magnetic moment deflection between the magnetic moment of the second free layer and the magnetic moment of the fixed layer is calculated, and the resistance state corresponding to the magnetic moment deflection is calculated as the second resistance state based on the magnetoresistance effect. The conversion of the magnetic moment of the second free layer is adjusted by controlling the magnitude of the current, thereby obtaining different magnetic moments of the free layer, and corresponding different resistance states are obtained based on the calculated magnetic moment deflection between the magnetic moment of the free layer and the magnetic moment of the fixed layer, wherein the direction of the magnetic moment of the fixed layer remains unchanged.

[0057] Optionally, the fixed layer ferromagnetic materials constituting this application include: CoFeB, CoFe, Co, and different combinations of the above three materials; wherein CoFeB is an alloy, and the atomic ratio includes Co20Fe60B20, Co40Fe40B20, or Co60Fe20B20; CoFe is an alloy, and the atomic ratio includes Co70Fe30, Co75Fe25, or Co85Fe15. The fixed layer can be a synthetic antiferromagnetic structure or a spin valve structure. After completing the magnetic tunnel junction, the entire film stack needs to be annealed. The annealing temperature range is 200℃-500℃, which is adjusted according to the thickness of the antiferromagnetic layer. The annealing magnetic field size is within 2T (Tesla), and the annealing direction is from top to bottom and from bottom to top of the entire structure simultaneously. Optionally, the thickness of each layer can be: the thickness of the heavy metal layer (for example, when the material is Pt) is 8 nm, the thickness of the antiferromagnetic layer (for example, when the material is IrMn) is 8 nm, the thickness of the free layer (for example, when the material is CoFeB) is 1.2 nm, the thickness of the non-magnetic barrier layer (for example, when the material is MgO) is 1.5 nm, the thickness of the fixed layer (for example, when the material is CoFeB) is 1.9 nm or the thickness of the fixed layer (for example, when the material is CoFe) is 0.5 nm, and the thickness of the covering layer (for example, when the material is Ta) is 2 nm.

[0058] In one embodiment, the first preset range is 10 microamperes μA to 10 milliamperes mA. By adjusting the current range, multi-resistance state storage from "0" to "10" can be achieved.

[0059] In one embodiment, the second preset range includes the following second preset values: 1μA, 2.5μA, 1mA, and 2.5mA. When the first current is 10μA, the second current is 1μA or 2.5μA, that is, each time the second current is adjusted to a fixed increase of 1μA or 2.5μA, when the second current is adjusted to a fixed increase of 1μA, multi-resistance-state storage of storage states from "0" to "10" can be achieved. When the second current is adjusted to a fixed increase of 2.5μA, multi-resistance-state storage of storage states from "0" to "4" can be achieved. When the first current is 10mA, the second current is 1mA or 2.5mA, that is, each time the reverse current is adjusted to a fixed increase of 1mA or 2.5mA, when the second current is adjusted to a fixed increase of 1mA, multi-resistance-state storage of storage states from "0" to "10" can be achieved. When the second current is adjusted to a fixed increase of 2.5mA, multi-resistance-state storage of storage states from "0" to "4" can be achieved.

[0060] In another embodiment, the difference between the second current and the first current can be increased or decreased by N times, and the upper limit of the increase is not greater than the maximum value of the first preset range. For example, when the first current is 2mA and the second current is 3mA, the difference between the second current and the first current is 1. At this time, the corresponding third resistance storage state finally formed is "3", and the lower limit of the decrease is not less than the minimum value of the first preset range. The lower limit of the decrease is greater than or equal to 0, which will not be repeated here.

[0061] like Figure 2 As shown, a second aspect of the embodiment of the present application provides a multi-state memory, the multi-state memory comprising:

[0062] a substrate and a magnetic tunnel junction covering the substrate,

[0063] The upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer and a free layer from bottom to top;

[0064] The heavy metal layer is configured to generate a target spin current when the current flowing therein changes from a first current to a second current;

[0065] The antiferromagnetic layer is used to flow the target spin current into the free layer via the antiferromagnetic layer, wherein a current value of the second current is less than or equal to a first preset value, and the first preset value is any value in a first preset range;

[0066] The free layer, the magnetic field used for the free layer generates a first spin-orbit torque in response to the target spin current, the antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from the first free layer magnetic moment to the second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, so that the resistance state of the multi-state memory is switched from the first resistance state to the second resistance state, the first resistance state is the resistance state corresponding to the first free layer magnetic moment, and the second resistance state is the resistance state corresponding to the second free layer magnetic moment.

[0067] Through the interaction between the above-mentioned layers, the resistance state of the polymorphic memory is switched from the first resistance state to the second resistance state, thereby realizing the storage of multiple resistance states by controlling the magnitude of the current. Moreover, the magnitude of the current is easier to control, thereby making it easier to obtain more stable multiple resistance states, reducing the difficulty of implementing polymorphic storage.

[0068] In one embodiment, the magnetic tunnel junction further includes a pinned layer above the free layer, the pinned layer being configured to determine a magnetic moment deflection between the magnetic moment of the second free layer and the magnetic moment of the pinned layer, and to calculate a resistance state corresponding to the magnetic moment deflection based on a magnetoresistance effect as the second resistance state. By controlling the magnitude of the current, the conversion of the magnetic moment of the second free layer is adjusted to obtain different magnetic moments of the free layer, and corresponding resistance states are obtained based on the calculated magnetic moment deflection between the magnetic moment of the free layer and the magnetic moment of the pinned layer, wherein the direction of the magnetic moment of the pinned layer remains unchanged.

[0069] In another embodiment, if Figure 3 As shown, the magnetic tunnel junction includes an antiferromagnetic layer, a free layer, a nonmagnetic barrier layer, a fixed layer, an antiferromagnetic coupling layer, a pinned layer, and a capping layer arranged from bottom to top. This structure is more stable overall, but slightly more complex and more expensive than the magnetic tunnel junction in the above embodiment. The antiferromagnetic coupling layer in the antiferromagnetic coupling structure can be made of materials including, but not limited to, Ru, Ir, and W, with a thickness of 0.2 nm to 1.0 nm.

[0070] A third aspect of the embodiments of the present application provides a storage medium on which computer-executable instructions are stored. When the computer-executable instructions are executed by a computing device, they can be used to implement the methods described in the aforementioned embodiments.

[0071] It should be understood that the above-mentioned specific embodiments of the present application are merely illustrative or explain the principles of the present application and do not constitute a limitation of the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present application should be included in the scope of protection of the present application. In addition, the claims attached hereto are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A polymorphic storage method, characterized in that: The method is applied to a multi-state memory, the multi-state memory including a substrate and a magnetic tunnel junction covering the substrate, wherein the upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer, a free layer, and a pinned layer from bottom to top. The method includes: When the current flowing into the heavy metal layer changes from a first current to a second current, the heavy metal layer generates a target spin current, and the target spin current flows into the free layer via the antiferromagnetic layer, wherein the current value of the second current is less than or equal to a first preset value, and the first preset value is any value in a first preset range; The magnetic field of the free layer generates a first spin-orbit torque in response to the target spin current; The antiferromagnetic layer switches from the first antiferromagnetic layer magnetic moment to the second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque; The free layer switches from a first free layer magnetic moment to a second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, so that the resistance state of the multi-state memory switches from a first resistance state to a second resistance state, wherein the first resistance state is a resistance state corresponding to the first free layer magnetic moment, and the second resistance state is a resistance state corresponding to the second free layer magnetic moment; The pinned layer includes a synthetic antiferromagnetic structure or a spin valve structure.

2. The polymorphic storage method according to claim 1, wherein: The current flowing into the heavy metal layer is changed from a first current to a second current, comprising: When the first current is a current in a first direction, the current value of the first current is the first preset value, the direction of the second current is opposite to that of the first current, and the current value of the second current is less than the first preset value; or, When the first current and the second current have the same direction, the difference between the second current and the first current is N times a second preset value, where N is an integer greater than or equal to 1, and the second preset value is a value within a second preset range that is smaller than the first preset value.

3. The polymorphic storage method according to claim 1, wherein: The direction of the magnetic moment of the second antiferromagnetic layer is the same as the direction of the magnetic moment of the second free layer.

4. The polymorphic storage method according to claim 1, wherein: The antiferromagnetic layer switches from a first antiferromagnetic layer magnetic moment to a second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from a first free layer magnetic moment to a second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, including: One or more first antiferromagnetic layer magnetic sequences of the antiferromagnetic layer are converted into second antiferromagnetic layer magnetic sequences under the action of the first spin-orbit torque, and any one or more second antiferromagnetic layer magnetic sequences of the antiferromagnetic layer serve as the second antiferromagnetic layer magnetic moment; One or more first free layer magnetic domains of the free layer are converted into second free layer magnetic domains under the action of the second antiferromagnetic layer magnetic order, and any one or more second free layer magnetic domains of the free layer serve as the second free layer magnetic moment.

5. The polymorphic storage method according to claim 1, wherein: The method further comprises: determining a magnetic moment deflection between a magnetic moment of the second free layer and a magnetic moment of the pinned layer; The resistance state corresponding to the magnetic moment deflection is calculated according to the magnetoresistance effect as the second resistance state.

6. The polymorphic storage method according to claim 1 or 2, characterized in that: The first preset range is 10 microamperes (μA) to 10 milliamperes (mA).

7. The polymorphic storage method according to claim 2, characterized in that: The second preset range includes the following second preset values: 1 μA, 2.5 μA, 1 mA, and 2.5 mA.

8. A polymorphic memory, characterized in that: The multi-state memory comprises: a substrate and a magnetic tunnel junction overlying the substrate; The upper surface of the substrate includes a heavy metal layer, and the magnetic tunnel junction includes an antiferromagnetic layer, a free layer and a fixed layer from bottom to top; The heavy metal layer is configured to generate a target spin current when the current flowing therein changes from a first current to a second current; The antiferromagnetic layer is used to flow the target spin current into the free layer via the antiferromagnetic layer, wherein a current value of the second current is less than or equal to a first preset value, and the first preset value is any value in a first preset range; The free layer, wherein a magnetic field for the free layer generates a first spin-orbit torque in response to the target spin current, the antiferromagnetic layer switches from a first antiferromagnetic layer magnetic moment to a second antiferromagnetic layer magnetic moment under the action of the first spin-orbit torque, and the free layer switches from a first free layer magnetic moment to a second free layer magnetic moment under the action of the second antiferromagnetic layer magnetic moment, so that the resistance state of the multi-state memory is switched from a first resistance state to a second resistance state, the first resistance state being a resistance state corresponding to the first free layer magnetic moment, and the second resistance state being a resistance state corresponding to the second free layer magnetic moment; The pinned layer includes a synthetic antiferromagnetic structure or a spin valve structure.

9. The multi-state memory according to claim 8, wherein: The pinned layer is used to determine the magnetic moment deflection between the magnetic moment of the second free layer and the magnetic moment of the pinned layer; The resistance state corresponding to the magnetic moment deflection is calculated according to the magnetoresistance effect as the second resistance state.

10. A storage medium having computer-executable instructions stored thereon, which, when executed by a computing device, is used to execute the method according to any one of claims 1 to 7.

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